The laptop screen is 'dead' and no USB power on boot

Most of the times, I just 'sleep' the laptop. Yesterday, I 'slept' the laptop and didn't use all day. Today morning, tried to boot it, it felt like it did boot (fan running etc) but the screen remained dead (as in the screen didn't power up). There was no power to USB ports either.

A quick googling led to many options.
- I removed RAM modules (4GB x 2) one by one to see if there is any faulty RAM module.
- Removed the battery and tried to 'reset' and used power cable to power up to see if anything changes.
- Connected laptop to the TV to try to get screen 'working', no effect. I could not decide whether its the screen or anything else.
(Since there is no USB power, I am not too sure if HDMI ports are live.)
- Last option, was to check the CMOS battery. Opened up the laptop (Toshiba A505-6005) and found that the battery is soldered to the motherboard.

I am not exactly well-versed with soldering so before I venture into it, is there anything else I can check for?
Can anyone guess any other problem?

Thanks in advance.

If you have a multimeter,then check the PSU output and also the power cable to the motherboard.
Should you proceed with the soldering,make sure you use a heatsink.Once toasted,motherboards have no further use.
Discolouration and distorted capacitors will tell you.

Run through these links for POST troubleshooting and beep codes:

What is POST?

Computer POST and beep codes

POST troubleshooting steps